1 reply to this topic

[Takechi]

Dear all

 

I would like to consult you about when shell and tube heat exchanger fouled. Is the heat transfer of hot side equal to heat transfer of cold side?.

 

I just confuse because my company evaluate performance of heat exchanger by calculate U_{actual /} Uclean

 

U_actual calculate only from one side of heat exchanger.

 

 

Milo

 

 

[Saml]

Milo,

Apart from losses to environment and transient conditions,  the heat removed from the hot side, is the same as the heat received by the cold side. However to calculate the Uactual you need at least either:

 

- One Flow 

- 4 Temperatures (in fact, the thermodynamic variables that allows to calculate the entalphy difference between inlet and outlet, that for no phase change and known composition it is usually temperature)

 

- Both Flows

- 3 Temperatures

 

Or if you have a pure condensing stream on one side (like steam) you need:

- The other side flow, inlet and outlet temperature.

- Operating pressure on the condensing side.

 

So wonder what it is being calculated "only from one side".